Originally posted by krisvictor
ooohhhh!! My brain hurts after reading threads in this forum. It's a good hurt.
With so much intelligence in this site, I shall never run out of ideas for debate! It's interesting to read about the goodah buddah or the big bad bible or even the overly-trodden evolution revolution; I love to read the entries and see into the spirit of people like Ivanho ...[text shortened]... how they were arranged in such a way as to produce a brain that can convey intelligent thought?
Atoms are the way subatomic particles naturally organize themselves because of the action of the natural forces of the universe.
Similarly, atoms naturally organize into molecules. According to someone (I don't know who came up with this or why), the Earth long ago had water and a primitive atmosphere which contained oxygen, nitrogen and some other atoms. Under these conditions, nucleotide triphosphates (NTPs) and amino acids spontaneously form when energy is added to the mix as Miller and others have demonstrated. NTPs are hypothesized to spontaneously polymerize when they are concentrated in aqueous solution. Such concentration might plausibly occur in tidal pools exposed to heat such that water with NTPs would slosh in and then the water evaporate due to the heat.
Once these ribonucleic acid polymers (RNA) formed, they could catalyze their own reproduction via base pairing with NTPs. RNA can act as other catalysts as well.
An evolutionary process would have begun in which the RNAs that reproduced most effectively would monopolize the supply of NTPs. Mutations in the RNAs would introduce variation and natural selection would weed out the less successful variations.
Phospholipid vesicles form spontaneously in water. RNA that was trapped within such vesicles would be at an evolutionary advantage as it would be easier for NTPs to get in than for the larger RNA products to get out. As more and more RNA molecules filled the vesicle, and maybe more phospholipid molecules enlarged the bilayer, the vesicle would bud off new protocells. The evolutionary process would work on these protocells to form true prokaryotic cells, and then would work on these over long periods of time to gradually form multicellular eukaryotic life. Nervous tissue evolved and it's organization evolved until the human brain came to be. Natural selection and variation (whether due to mutations and/or some sort of Lamarkian effect) is what drove evolution.